• Title/Summary/Keyword: 연기거동

Search Result 121, Processing Time 0.029 seconds

A Numerical Study of an Effect of the Aspect Ratio on Smoke Movement in funnel Fires (터널 화재시 종횡비에 따른 연기 거동에 관한 수치해석적 연구)

  • 이성룡;김충익;유홍선
    • Fire Science and Engineering
    • /
    • v.18 no.2
    • /
    • pp.1-6
    • /
    • 2004
  • In this study, numerical simulations were conducted to analyze an effect of the aspect ratio on smoke movement in tunnel fires using FDS 3.0. It was confirmed an application for tunnel fires in comparison with experimental results. The results showed relatively good agreement with experimental data within 1$0^{\circ}C$. Clear height of CFD by velocity distribution was about 3% higher than that of experiment. Smoke movement was confirmed by the analysis of temperature and velocity field. Results from variation of the aspect ratio showed good agreement with experimental data. The temperature at the vicinity of the fire source became lowly with the increase of the aspect ratio. But, decrease rate of the temperature was reduced by the decrease of the heat loss to the width direction.

A Study on Ventilation Effects on Smoke Behavior in Rescue Station for Tunnel Fires (철도터널 화재시 구난역 내의 연기거동에 미치는 배연효과에 관한 연구)

  • Jang, Won-Cheol;Kim, Dong-Woon;Lee, Seong-Hyuk;Ryou, Hong-Sun
    • Journal of the Korean Society for Railway
    • /
    • v.11 no.3
    • /
    • pp.294-299
    • /
    • 2008
  • The present study investigates the ventilation effects on smoke spreading with the rescue stations. Experiments for tunnel fires were carried out for n-heptane pool em at different fire locations, and the heat release rates (HRR) were obtained by addition, using the commercial code (FLUENT), the present article presents numerical results for smoke behavior in railway tunnels with rescue station, and it uses the MVHS (Modified Volumetric Heat Source) model for estimation of combustion products resulting from the fire source determined from the HRR measurement. As a result, it is found that smoke propagation is prevented successfully by the fire doors located inside the cross-passages and especially, the smoke behavior in the accident tunnel can be controlled through the ventilation system because of substantial change in smoke flow direction in the cross-passages.

An Experimental Study on Smoke Movement by the External Wind in Road Tunnel Fires (도로터널 화재 시 외부 바람에 의한 연기거동 특성에 관한 실험적 연구)

  • Lee, Sung-Ryong
    • Tunnel and Underground Space
    • /
    • v.24 no.4
    • /
    • pp.308-315
    • /
    • 2014
  • In this study, reduced scale experiments were carried out to evaluate the effect of external wind in a road tunnel fire. Experiments were conducted in a $1.1m{\times}0.5m{\times}50.4m$ tunnel. 4.5 litter gasoline was used as a fuel. Temperature, oxygen and carbon monoxide concentration were measured. Smoke reaching time to the tunnel exit was affected by the external wind. When a fire was fully developed, wind effect is reduced compared with the early stage of a fire. CO concentration was reached at more than 1,500 ppm.

An Experimental Study of Smoke Control in Tunnel Fires with Jet Fan (터널화재시 제트팬에 의한 연기제어에 관한 실험적 연구)

  • 이성룡;김충익;유홍선;방기영
    • Tunnel and Underground Space
    • /
    • v.12 no.2
    • /
    • pp.92-98
    • /
    • 2002
  • In this study reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with jet fan, The 1/20 scale experiments were carried out under the froude scaling using gasoline pool fire range from 6.6 to 12.5 cm in diameter with total heat release rate from 0.714 to 4.77 kW. In the case of fires under the 2.5kW, backlaying was reduced about 40cm and smoke was effectively controled in downstream of the fan when operating the fan. The smoke layer was moved down and the ceiling temperature was decreased compared to that of without fan case in upstream of the fan, but the temperature in the lower part of the tunnel was increased.

A Numerical Study of Smoke Movement in Atrium Fires with Ceiling Hea Flux (천장에 열 유속을 갖는 대형 공간에서 화재 발생시 연기거동에 대한 수치해석적 연구)

  • 정진용;유홍선;김성찬;김충익
    • Fire Science and Engineering
    • /
    • v.13 no.4
    • /
    • pp.20-29
    • /
    • 1999
  • This paper describes the smoke filling process of a fire field model based on a self-developed SMEP(Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of atrium space containing a ceiling heat flux. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k- epsilon turbulence model with buoyancy term. Compressibility is assumed and the perfect gas law is used. The results of the calculated upper-layer average temperature and smoke layer interface height has shown reasonable agreement compared with the zone models. The zone models used are the CFAST developed at the Building and Fire Research Laboratory NIST U.S.A. and the NBTC one-room of FIRECALC developed at CSIRO, Australia. The smoke layer interface heights that are important in fire safety were not as sensitive as the smoke layer temperature to the nature of ceiling heat flux condition.

  • PDF

Numerical Investigation of Smoke Behavior in Rescue Station for Tunnel Fire (철도터널 화재 시 구난역 내의 연기거동에 대한 수치해석 연구)

  • Hong, Sa-Hoon;Ro, Kyung-Chul;Ryou, Hong-Sun;Lee, Seong-Hyuk
    • Journal of the Korean Society for Railway
    • /
    • v.12 no.1
    • /
    • pp.25-30
    • /
    • 2009
  • The present study deals with numerical investigation for smoke behavior in rescue station by using the commercial CFD code (FLUENT Ver 6.3). With the use of the MVHS(Modify Volumetric Heat Source) model modified from the original VHS(Volumetric Heat Source) model, a 10 MW mode was adopted for simulation and the MVHS model can describe the generation of product and the oxygen consumption at the stoichiometric state. In addition, the present simulation includes the species conservation equations for the materialization of heat source and the estimation of smoke movement. From the results, the smoke flows are moving along the ceiling because of thermal buoyancy force and as time goes, the smoke gradually moves downward at the vicinity of the entrance. Moreover, without using ventilation, it is found that the smoke flows no longer spread across the cross-passages because the pressure in the non-accident tunnel is higher than that in the accident tunnel.

An Experimental Study of Smoke Movement in Tunnel Fires with Aspect Ratio of Tunnel Cross Section (터널 화재시 터널 단면의 종횡비에 따른 연기 거동에 관한)

  • Lee, Sung-Ryong;Ryou, Hong-Sun;Kime, Choong-Ik
    • Proceedings of the KSME Conference
    • /
    • 2003.11a
    • /
    • pp.115-120
    • /
    • 2003
  • In this study, smoke movement in tunnel fires was investigated with various aspect ratio(0.5, 0.667, 1.0, 1.5, 2.0) of tunnel cross section. Reduced-scale experiments were carried out under the Froude scaling using 8.27 kW ethanol pool fire. Temperatures were measured under the ceiling and vertical direction along the center of the tunnel. Smoke front velocity and temperature decrease rate were reduced as higher aspect ratio of the tunnel cross-section. Smoke movement was evaluated by analysis of vertical temperature distribution 3 m downstream from the fire source. Elevation of smoke interface according to N percent rule was under about 60% of tunnel height.

  • PDF

Numerical Simulation on the Heat and Smoke Flow Phenomena Due to the Fire in a Cyclodrome (경륜장 내부의 화재발생에 따른 열 및 연기 거동에 대한 수치적 연구)

  • 박원희;김태국;손봉세
    • Fire Science and Engineering
    • /
    • v.17 no.3
    • /
    • pp.13-19
    • /
    • 2003
  • In this paper, numerical calculations are conducted to predict the characteristics of the heat transfer and smoke propagation in a cydodrome. The gas flow velocity and temperature around the origin of the fire is obtained by using a plume model and the turbulent flow characteristics are considered by standard $textsc{k}$-$\varepsilon$ turbulent model. In this study, the transient thermal behavior can be used for designing fire detection of large rooms.